Chromosomal microarray whole genome view of the osteosarcoma from the younger brother. (A, frozen tissue), the first (B, FFPE tissue) and the second (C, frozen tissue) osteosarcoma from the older brotherTop view in all three graphics: Total copy number view showing gains and losses (from left to right: chromosomes 1–22 followed by X and Y); Bottom view: Allele difference (A and C) or B-allele frequency plots (B) confirming the gains and losses observed in the top copy number view and demonstrating LOH. All three tumors showed complex copy number alterations with a high level of genomic instability consistent with osteosarcoma. Red arrows indicate the alterations in 13q and 17p in the three tumors. The tumor from the proband (A) demonstrated gain and LOH of 13q and 17p, including RB1 and TP53, respectively. The first tumor from the older brother (B) had a deletion of chromosome13 and gain of 17p. The second tumor from the older brother (C) showed copy number copy number neutral LOH for 13q and 17p.